The present invention relates generally to stabilizers for use with backhoes or other similar vehicle mounted excavating devices, and more particularly, to a locking mechanism for the stabilizers while in a raised position.
Backhoe frames typically include stabilizers on their outboard sides generally perpendicular to the longitudinal axis of the backhoe boom to support the backhoe and the mounting vehicle during use. Stabilizers which pivot between raised and lowered or working positions are individually driven by hydraulic cylinders in response to operator actuation. When lowered during excavation, the stabilizers stabilize the vehicle to avoid lateral and/or forward movement when working the backhoe. A hydraulic circuit lock-out is often used in the hydraulic drive circuit for the stabilizer hydraulic cylinders to prevent fluid from leaking from the hydraulic cylinders after the stabilizers have been positioned. The hydraulic locks work with the stabilizers in their retracted position when the vehicle is traveling or being stored, and in their extended position during excavation.
However, a problem has arisen with the lock-out in the hydraulic circuit, even those with pilot operated check valves, in that when the stabilizers reach the raised or stored position a substantial amount of downward pivoting of the stabilizer occurs with little movement of the rod of the hydraulic cylinders permitted by any small hydraulic fluid leaks from the hydraulic cylinders.